<!DOCTYPE html>
<html>
<head>
  <style>

  td { color:blue; font-weight:bold; }
  </style>
  <script src="http://code.jquery.com/jquery-latest.js"></script>
</head>
<body>
  <table>
    <tr><td>Row 1</td></tr>
    <tr><td>Row 2</td></tr>

    <tr><td>Row 3</td></tr>
  </table>
<script>$("tr:first").css("font-style", "italic");</script>

</body>
</html>